Nemotron 3 Ultra Free fails with "Upstream idle timeout exceeded" during tool execution #33714

Bug Report

Description

Upstream idle timeout exceeded occurs when using Nemotron 3 Ultra Free in opencode during long responses.

The issue does not appear to happen with other models (only tested/observed with Nemotron 3 Ultra Free).

The model can start a task normally, perform tool calls successfully, then during a long generation the stream times out. After the timeout, subsequent tool operations may fail.

Error:
write failed
"Upstream idle timeout exceeded"

Steps to reproduce

1. Open opencode.

2. Select model: Nemotron 3 Ultra Free

3. Start a large coding/planning task requiring multiple tool calls.

4. Let the model generate a long response.

5. After some time, the response fails with: Upstream idle timeout exceeded

6. Tool calls after the timeout may fail even though previous ones succeeded.

Expected behavior

The model should continue generation or recover from the timeout without breaking the workflow.

Actual behavior

The generation stream times out and interrupts the task.

System information

• OS: Windows 10 pro
• opencode version: latest version (v1.17.10)
• Provider: opencode zen
• Model: Nemotron 3 Ultra Free
• Other models tested: All others work perfectly normally

Additional context

This seems specific to Nemotron 3 Ultra Free, possibly related to streaming timeout handling or provider-side idle limits. I think it's because nemtoron 3 ultra has a slow tps. I suggest setting higher time out limits :)